AES E-Library

A 1W filter-less power DAC featuring 104dBA SNR and EMI spreading is presented. Pre-distortion algorithms are used to reduce harmonic distortion inherent to the employed modulation process, and an oversampling noise shaper allows reducing modulator clock speed to facilitate hardware implementation while keeping high-fidelity quality. No analog circuits exist from I2S interface to speaker, leading to zero output offset and good efficiency even at medium/low power levels. 1.2V digital and 2.7V-5V output supplies are used. Active area is 0.94mm2 in a 0.13micron CMOS process. Total harmonic distortion at maximum level is about 0.2%.